1. Field of The Invention
The invention relates to an electric connector, particularly to a Universal Serial Bus (USB) B-type plug connector, and more particularly to an improved USB B-type plug connector concerning the casing shield frame and contact pieces thereof.
The USB connector is a recently developed connector which can be used to replace most of the input/out (I/O) connectors, for example, D-Sub connectors and Mini-Dins as can be seen in the back of a computer.
2. The Prior Art
With the advancement of communication and computer technology, electrical connectors are being constantly improved to meet more and more strict requirements.
FIG. 1 shows a prior art input/output connector in accordance with U.S. Pat. No. 4,516,822 ('822 patent) that has poor electrical connecting characteristic between the cable and contact pieces of the connector.
FIGS. 2 and 3 show another two prior art connectors in accordance with U.S. Pat. Nos. 5,073,130 and 5,267,882, respectively. Although these two prior art connectors can overcome the problem of the '822 patent, they both have a complicated structure, which causes difficulty in connector manufacturing and assembly. Moreover, it is not very convenient to connect the contact pieces of these two connectors with cables.
Additionally, Taiwan Patent Application Nos. 83310726, 81300211 and 81217896, and U.S. Pat. Nos. 5,013,262, 5,017,156 and 5,221,212 disclose some other connectors which also have the above mentioned disadvantages.
Therefore, an objective of the invention is to provide an electrical connector, particularly a USB B-type plug connector, which has a simple structure so that it can be easily manufactured and has a lower cost.
Another objective of the invention is to provide an electrical connector, particularly a USB B-type plug connector, with a casing shield frame which can be easily manufactured and assembled.
A further objective of the invention is to provide an electrical connector, particularly a USB B-type plug connector, with contact pieces which can easily connect with a cable and has good electrical and mechanical connecting characteristics therewith.
Still a further objective of the present invention is to provide an electrical connector, particularly a USB B-type plug connector, with contact pieces which can be easily mounted in a connector's dielectric casing.